Determination of Surface Precipitation Type Based on the Data Fusion Approach     

Marek PÓŁROLNICZAK  Leszek KOLENDOWICZ  Bartosz CZERNECKI  Mateusz TASZAREK  Gabriella TÓTH 《大气科学进展》2021,38(3):387-399

Hazardous events related to atmospheric precipitation depend not only on the intensity of surface precipitation,but also on its type.Uncertainty related to determination of the precipitation type(PT)leads to financial losses in many areas of human activity,such as the power industry,agriculture,transportation,and many more.In this study,we use machine learning(ML)algorithms with the data fusion approach to more accurately determine surface PT.Based on surface synoptic observations,ERA5 reanalysis,and radar data,we distinguish between liquid,mixed,and solid precipitation types.The study domain considers the entire area of Poland and a period from 2015 to 2017.The purpose of this work is to address the question:“How can ML techniques applied in observational and NWP data help to improve the recognition of the surface PT?”Despite testing 33 parameters,it was found that a combination of the near-surface air temperature and the depth of the warm layer in the 0-1000 m above ground level(AGL)layer contains most of the signal needed to determine surface PT.The accrued probability of detection for liquid,solid,and mixed PTs according to the developed Random Forest model is 98.0%,98.8%,and 67.3%,respectively.The application of the ML technique and data fusion approach allows to significantly improve the robustness of PT prediction compared to commonly used baseline models and provides promising results for operational forecasters.  相似文献   

Brown earth and podzol: soil genesis illuminated by microfossil analysis     

SVEND TH. ANDERSEN 《Boreas: An International Journal of Quaternary Research》1979,8(1):59-73

Andersen, S. Th. 1979 03 01: Brown earth and podzol: soil genesis illuminated by microfossil analysis. Boreas , Vol. 8, pp. 59–73. Oslo. ISSN 0300–9483.
Pollen and other plant microfossils were studied in soil profiles from a Fagus-Quercus petraea woodland in eastern Jutland, Denmark. Fungal hypha fragments in the soil show characteristic length frequency distributions, which indicate comminution by large arthropods and microarthropods (Oribatei) during the burial. Distribution of the hypha fragments within the podzol indicates development from a former brown earth. The pollen sequence in a humus deposit reflects recent vegetational development. Modification of pollen assemblages in the mineral soils can be explained by mixing during burial by soil fauna. Development from brown earth to podzoloid and podzol follows the models assumed by pedologists. The various stages are related to vegetational changes and the processes were completed within a few hundred years.  相似文献   

X-ray luminous IRAS galaxies     

TH. Boller  E. J. A. Meurs  M. Dennefeld  H. Fink 《Astrophysics and Space Science》1993,205(1):43-47

A sample of 14708 extragalactic IRAS sources selected from the Point Source Catalog via statistical classification has been cross-correlated with the ROSAT All Sky Survey (Bolleret al., 1992). 244 galaxies emerge as being detected both by ROSAT and IRAS.The most interesting point is the discovery of a dozen of normal spirals whose X-ray luminosities reach nearly 10⁴³ erg s^–1 (0.1–2.4 keV), higher than previous detection limits of a few 10⁴¹ erg s^–1 (Stockeet al. 1991; Green, Anderson and Ward, 1992). We obtained optical spectra for nine of them, showing Seyfert spectra for three of the objects (thus previous mis-classifications), spectra close to LINERs for two further objects and normal IRAS galaxy spectra for the last four.In the case of normal galaxies, the source of energy is not clear yet and could be related to the high rate of star formation likely to occur in the central regions or also to a low level active nucleus. The study of these objects is of interest to the nature of LINERs and, more generally, to possible relations between AGN and starbursts (Sanderset al., 1988).  相似文献   

Developing an Erosion Risk Map Using Soft Computing Methods (Case Study at Sifnos Island)     

Gournellos  TH.  Evelpidou  N.  Vassilopoulos  A. 《Natural Hazards》2004,31(1):63-83

The erosional processes depend on various variables such as lithology, topography,drainage system, rock structure and climatic conditions. The quantitative evaluationof some of the above geological and geomorphological parameters is of primaryimportance for the purpose of developing erosion risk maps. These maps can becomeuseful tools for developing appropriate strategies on environmental protection, hazardassessment and regional planning.The island of Sifnos, in Cyclades, was chosen as a case study, where in the final map of the sub-basins of this island, erosion risk distribution is presented.  相似文献   

CANCELLING MULTIPLE REFLECTIONS BY FEEDBACK *     

K. KOEHLER  TH. KREY  H. WACHHOLZ 《Geophysical Prospecting》1974,22(4):652-666

For horizontal layering and plane horizontal impulsive wavefronts it is theoretically possible to get rid of multiple reflections by a feedback procedure which can easily be derived using raypath philosophy. To reduce the increase of noise inherent in the method the precise theoretical formulae are altered in such a manner that a practical application becomes possible. For this purpose the autocorrelation will be used. Application of the new process to a CRP section where the shot geophone distances in the field had not been long enough to attenuate multiple reflections effectively gave favourable results.  相似文献   

ENSIP: the El Niño simulation intercomparison project     

M. Latif  K. Sperber  J. Arblaster  P. Braconnot  D. Chen  A. Colman  U. Cubasch  C. Cooper  P. Delecluse  D. Dewitt  L. Fairhead  G. Flato  T. Hogan  M. Ji  M. Kimoto  A. Kitoh  T. Knutson  H. Le Treut  T. Li  S. Manabe  O. Marti  C. Mechoso  G. Meehl  S. Power  E. Roeckner  J. Sirven  L. Terray  A. Vintzileos  R. Voß  B. Wang  W. Washington  I. Yoshikawa  J. Yu  S. Zebiak 《Climate Dynamics》2001,18(3-4):255-276

An ensemble of twenty four coupled ocean-atmosphere models has been compared with respect to their performance in the tropical Pacific. The coupled models span a large portion of the parameter space and differ in many respects. The intercomparison includes TOGA (Tropical Ocean Global Atmosphere)-type models consisting of high-resolution tropical ocean models and coarse-resolution global atmosphere models, coarse-resolution global coupled models, and a few global coupled models with high resolution in the equatorial region in their ocean components. The performance of the annual mean state, the seasonal cycle and the interannual variability are investigated. The primary quantity analysed is sea surface temperature (SST). Additionally, the evolution of interannual heat content variations in the tropical Pacific and the relationship between the interannual SST variations in the equatorial Pacific to fluctuations in the strength of the Indian summer monsoon are investigated. The results can be summarised as follows: almost all models (even those employing flux corrections) still have problems in simulating the SST climatology, although some improvements are found relative to earlier intercomparison studies. Only a few of the coupled models simulate the El Niño/Southern Oscillation (ENSO) in terms of gross equatorial SST anomalies realistically. In particular, many models overestimate the variability in the western equatorial Pacific and underestimate the SST variability in the east. The evolution of interannual heat content variations is similar to that observed in almost all models. Finally, the majority of the models show a strong connection between ENSO and the strength of the Indian summer monsoon.  相似文献   

Toxicity testing,risk assessment,and options for dredged material management   总被引：3，自引：0，他引：3  

Munns WR  Berry WJ  Dewitt TH 《Marine pollution bulletin》2002,44(4):294-302

Programs for evaluating proposed discharges of dredged material into waters of the United States specify a tiered testing and evaluation protocol that includes performance of acute and chronic bioassays to assess toxicity of the dredged sediments. Although these evaluations reflect the toxicological risks associated with disposal activities to some degree, analysis activities are limited to the sediments of each dredging project separately. Cumulative risks to water column and benthic organisms at and near the designated disposal site are therefore difficult to assess. An alternate approach is to focus attention on the disposal site, with the goal of understanding more directly the risks of multiple disposal events to receiving ecosystems. Here we review current US toxicity testing and evaluation protocols, and describe an application of ecological risk assessment that allows consideration of the temporal and spatial components of risk to receiving aquatic ecosystems. When expanded to include other disposal options, this approach can provide the basis for holistic management of dredged material disposal.  相似文献   

THIRTIETH MEETING OF THE EUROPEAN ASSOCIATION OF EXPLORATION GEOPHYSICISTS, HELD IN SALZBURG, 5th–7th JUNE, 1968     

TH. KREY 《Geophysical Prospecting》1968,16(3):305-311

  相似文献   

C. L. SARAZIN: X-ray emission from clusters of galaxies. Cambridge University Press,Cambridge/New York/New Rochelle/Melbourne/Sydney, 1988, Preis: £ 32.50. ISBN 0 521 32957 4     

TH. Boller 《Astronomische Nachrichten》1989,310(5):362-362

  相似文献